Mobile displays are increasingly being used to watch video. Currently their quality, in terms of pixel dimensions, contrast ratio, color gamut and bit-depth are typically inferior to stationary counterparts such as LCD TVs. However, in some applications, the quality lost due to these inferiorities may be acceptable when balanced with the increased convenience of a smaller mobile display. While the quality and performance of mobile displays is rapidly increasing, their size is an element of their portability and will always be less than that of stationary devices. The small size of these mobile displays generally results in a smaller field of view, which may be quantified in visual degrees. Viewing distance may also affect the field of view and a varying viewing distance can have a detrimental impact on viewing quality.
An important and frequent application for mobile displays is viewing image and video content during transportation. This may occur while commuting or traveling on a bus, subway, train, airplane or other vehicle. Even vehicle operators may use mobile or compact vehicle displays for navigation and vehicle condition assessment. Small displays are often used for automobile and airplane navigation and instrumentation. In these transportation applications, there is often a great deal of movement of the user relative to the display. This is often the result of irregular roadway surfaces or atmospheric conditions, which can jostle and bump a user relative to the vehicle and/or display. This movement often results in an undesirable and aperiodic vibration or random shaking, which makes video and image consumption difficult.
During transportation, a display may be difficult to see for a number of reasons. Fine details (high spatial frequencies) may be “smeared” due to motion blur. This can be caused by relative motion between the display and the eye combined with the eye's temporal response. Multiple edges can also cause undesirable masking throughout the image. The shaking display may contain multiple edges due to saccadic eye movements that don't land where they are anticipated due to the relative motion. Motion sickness can also affect video quality. This may be caused by a mismatch between eye movements and the vestibular canals of the ear. Headaches also often result from video consumption while traveling. This may result from excessive corrective eye movements and possible motion blur and multiple edge factors.